Along with the introduction of a smart grid (next-generation grid-system), smart meters including a communication and controlling function is becoming widely used.
On the other hand, the number of appliances, such as an air conditioner, which are used at home and having communication functions is increasing. Home energy management system (HEMS) which controls the appliances at home by a HEMS-controller using the communication functions of such appliances is gaining attention.
Furthermore, through the communication between the smart meters, the HEMS-controllers and the appliances, provision of various services is considered which is made possible, for example, by transmitting control signals, such as demand response (DR) signal, from the smart meters to the HEMS controllers and appliances.